Throughout various applications, consistent and accurate locating of components and surface features on the components is generally desired. Locating of the components and surface features thereon can facilitate subsequent operations performed on or to the components and surface features.
One application wherein consistent and accurate locating is desired is in applications wherein components are subjected to numerous extreme conditions (e.g., high temperatures, high pressures, large stress loads, etc.). Over time, an apparatus's individual components may suffer creep and/or deformation that may reduce the component's usable life. Such concerns might apply, for instance, to some turbomachines, such as gas turbine systems.
Turbomachines are widely utilized in fields such as power generation and aircraft engines. For example, a conventional gas turbine system includes a compressor section, a combustor section, and at least one turbine section. The compressor section is configured to compress air as the air flows through the compressor section. The air is then flowed from the compressor section to the combustor section, where it is mixed with fuel and combusted, generating a hot gas flow. The hot gas flow is provided to the turbine section, which utilizes the hot gas flow by extracting energy from it to power the compressor, an electrical generator, and other various loads.
During operation of a turbomachine, various components (collectively known as turbine components) within the turbomachine and particularly within the turbine section of the turbomachine, such as turbine blades, may be subject to creep due to high temperatures and stresses. For turbine blades, creep may cause portions of or the entire blade to elongate so that the blade tips contact a stationary structure, for example a turbine casing, and potentially cause unwanted vibrations and/or reduced performance during operation.
Accordingly, it is desirable to monitor components for creep. One approach to monitoring components for creep is to configure strain sensors on the components, and analyze the strain sensors at various intervals to monitor for deformations associated with creep strain. However, such deformation can in many cases be on the order of 0.01% of an original dimension, thus requiring specialized equipment for strain monitoring. Presently known acquisition tools and techniques for monitoring such strain sensors may in some cases not provide the desired sufficiently low-distortion, high-contrast, small scale images for these applications.
Accordingly, alternative systems and methods for monitoring component strain are desired in the art. Further, alternative data acquisition devices and methods for analyzing reference objects, such as passive strain indicators, are desired in the art. Systems, devices and methods which provide sufficiently low-distortion, high-contrast, small scale images for component passive strain indicator monitoring would be particularly advantageous.